Driver to drive?

[John Larkin]

On Tue, 22 Nov 2011 01:45:25 -0600, John Fields
<jfields@austininstruments.com> wrote:

On Mon, 21 Nov 2011 15:17:43 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 21 Nov 2011 13:16:30 -0600, John Fields
jfields@austininstruments.com> wrote:

On Sun, 20 Nov 2011 16:33:39 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 20 Nov 2011 17:56:24 -0600, John Fields
jfields@austininstruments.com> wrote:

On Sun, 20 Nov 2011 15:06:52 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 20 Nov 2011 16:42:39 -0600, John Fields
jfields@austininstruments.com> wrote:

On Sun, 20 Nov 2011 09:25:29 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 20 Nov 2011 08:16:21 -0800, Fred Abse
excretatauris@invalid.invalid> wrote:

On Sat, 19 Nov 2011 14:14:45 -0800
John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

Lots of online calculators are available.

I use this. I'm not sure how good or otherwise it looks in Excel, it was made using Sun Microsystems' Star Office, and exported as XLS. I hope the bitmap appears in the right place to overlay the value fields, I don't have Excel, to try it.

It produces theoretically image-matched attenuators for any combination of input and output resistances and any value of attenuation. Unrealizable combinations just result in negative values.

Derived from Radiotron Designer's Handbook, Chapter 4, "Theory of Networks", Sect. 8(v) "Image impedances and image transfer constant of four-terminal networks". Equations 17a thru 17f apply. There's a neat trick to get rid of the hyperbolic functions.

I wrote it about 30 years ago, as an HP41CV calculator app, and subsequently made a spreadsheet out of it.

See attached file.


Ooh, very nice. Thanks. JF can use that to fix up his design.

---
Actually, I'm close to fixing the math errors in my design, which seem
to have come from a trusted source, and which I'll post when I'm done.

You must mean formerly trusted source.

---
Nope, they're still trusted, by-and-large, because of previous
flawless performance.

If I get a bad hit again, though, they'll bear a little closer
watching.

Kinda like where you are now, where truth bows to face and I must
therefore consider you less than trustworthy.

All you have to do is look at the values of the first tee, which I
did, and it's obvious that it won't attenuate 32 dB. I don't trust
anything without giving it a sanity check.

---
PKB, since didn't your recent little resistor fiasco come about
because of excessive trust and inadequate sanity check?

Resistor fiasco? You mean the 0.05% thinfilms? Not the same thing at
all.

---
ISTR that you trusted your vendor enough to supply you with the right
stuff that you didn't do the sanity check of an incoming inspection
and, consequently, you got bit on the ass for your fox paws.

We have 5325 different parts in stock, 2.08 million pieces, so things
like that happen once in a while. We can't possibly incoming inspect
every part we buy. Imagine setting up test jigs for opamps,
microprocessors, FPGAs, bare PC boards, transformers, sheet matal, all
that. I have done flight hardware for spacecraft, where every single
part is tested and certified and traceable, and that's absurdly
expensive.

We do have procedures for picking up on parts problems in production
test, or from field returns, and investigating any patterns. That's
how we caught the resistor problem. In fact, it was a BIST reutine run
on an RTD acquisition section that found it, namely a circuit that
uses two resistors and checks them against one another.

Which airplanes do you have stuff flying on, or you supply GSE for,
anyway?

We don't have much actually flying. Some on the U2, some heads-up
display stuff on some AH130s. Most of our stuff is used in engine and
FADEC development and test cells (United Airlines uses our gear to
test APUs). We do some ground test stuff for B52 radars. That's a good
mix, aerospace but no mil or FAA certifications, which are a lot of
work.

---

Trust is no substitute for checking. As systems get more complex, the
margin for risk goes down.

Spare me the pontification of platitudes, blowhard.

Check your math, doofus.

---
All in good time, and at my leisure.

Did you use one of those online calculators? A lot of them are plain
wrong. I also suspect a lot of people are copying one anothers'
javascript, because I see the same wrong calculators in multiple
places.

A lot of microstrip-type calculators are wrong. Try a really wide
trace; the bad ones will report a negative impedance.

We could start a list of bad online calculators.

John

 

[Baron]

John Larkin Inscribed thus:

Did you use one of those online calculators? A lot of them are plain
wrong. I also suspect a lot of people are copying one anothers'
javascript, because I see the same wrong calculators in multiple
places.

A lot of microstrip-type calculators are wrong. Try a really wide
trace; the bad ones will report a negative impedance.

We could start a list of bad online calculators.

John

Now that could be a good idea ! But it shouldn't prevent checking and
confirming a result.

--
Best Regards:
Baron.

 

[Jim Thompson]

On Tue, 22 Nov 2011 22:40:14 +0000, Baron <baron@linuxmaniac.net>
wrote:

John Larkin Inscribed thus:
Did you use one of those online calculators? A lot of them are plain
wrong. I also suspect a lot of people are copying one anothers'
javascript, because I see the same wrong calculators in multiple
places.

A lot of microstrip-type calculators are wrong. Try a really wide
trace; the bad ones will report a negative impedance.

We could start a list of bad online calculators.

John

Now that could be a good idea ! But it shouldn't prevent checking and
confirming a result.

We could start a list of bad online circuit "designs" by Larkin ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[John S]

On 11/22/2011 5:15 PM, Jim Thompson wrote:

On Tue, 22 Nov 2011 22:40:14 +0000, Baron<baron@linuxmaniac.net
wrote:

John Larkin Inscribed thus:
Did you use one of those online calculators? A lot of them are plain
wrong. I also suspect a lot of people are copying one anothers'
javascript, because I see the same wrong calculators in multiple
places.

A lot of microstrip-type calculators are wrong. Try a really wide
trace; the bad ones will report a negative impedance.

We could start a list of bad online calculators.

John

Now that could be a good idea ! But it shouldn't prevent checking and
confirming a result.

We could start a list of bad online circuit "designs" by Larkin ;-)

...Jim Thompson

Very second-childhoodish of you Jim.

 

[tm]

"DoN. Nichols" <BPdnicholsBP@d-and-d.com> wrote in message
news:slrnjcom60.2vi.BPdnicholsBP@Katana.d-and-d.com...

On 2011-11-22, dagmargoodboat@yahoo.com <dagmargoodboat@yahoo.com> wrote:
On Nov 21, 9:08 pm, "DoN. Nichols" <BPdnichol...@d-and-d.com> wrote:
On 2011-11-21, dagmargoodb...@yahoo.com <dagmargoodb...@yahoo.com
wrote:

[ ... ]


O.K. Do you know the maximum voltage that the solar panel is
likely to produce? And the voltage drop on the LED? I know that
silicon diodes are typically between 600 mV and 750 mV. Also, any clues
as to the maximum voltage that the calipers can tolerate long term?

[ ... ]

You use the LED as a shunt regulator.




tm

 

[John Larkin]

On Tue, 22 Nov 2011 17:40:28 -0600, John S <sophi.2@invalid.org>
wrote:

On 11/22/2011 5:15 PM, Jim Thompson wrote:
On Tue, 22 Nov 2011 22:40:14 +0000, Baron<baron@linuxmaniac.net
wrote:

John Larkin Inscribed thus:
Did you use one of those online calculators? A lot of them are plain
wrong. I also suspect a lot of people are copying one anothers'
javascript, because I see the same wrong calculators in multiple
places.

A lot of microstrip-type calculators are wrong. Try a really wide
trace; the bad ones will report a negative impedance.

We could start a list of bad online calculators.

John

Now that could be a good idea ! But it shouldn't prevent checking and
confirming a result.

We could start a list of bad online circuit "designs" by Larkin ;-)

...Jim Thompson

Very second-childhoodish of you Jim.

Heck, he's up to childhood 2.5.

John

 

[Grumpy]

I suppose nobody under fifty knows how to read a real vernier, or a slide
rule for that matter ;-(

Unfortunately, most of us have to use a digital vernier, because we can't
SEE the real vernier!

 

[John Larkin]

On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy into
the
battery by letting the generator output voltage stretch its legs so to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.


Bwahahahahaha! So this was the original post? Bwahahahahaha!

...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?


Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Unfortunately my workshop has been dismantled for refurbishing and most of
the stuff crammed into the shed - so no room to work in there either.

When I tried LTspice I found it a PITA to use - maybe while deprived of my
workshop I should give it another chance.


I love LT Spice. It's not hard to use, and well worth the short
learning curve.

Here, try this:


Thanks - might download it tomorrow.

I committed a Great Sin on Friday: I *designed* a circuit by fiddling
with Spice. It's a double-terminated LC filter feeding an opamp driver
diffamp, an ADA4950-1, with an offset generator voltage divider, and
all sorts of entangled loadings. Looking at the algebra, I bailed.
Since I'd probably want to sim it to check any computed (and stocked!)
parts values, why not just Spice it and fiddle?

ftp://jjlarkin.lmi.net/ESM_sig_in.pdf

John

 

[NT]

On Dec 4, 10:06 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"



gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy into
the
battery by letting the generator output voltage stretch its legs so to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.

Bwahahahahaha!  So this was the original post?  Bwahahahahaha!

                                       ...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?

Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Its very doable. I had no idea those old dynamos put out so much.


NT

 

[Fred Bloggs]

On Dec 4, 5:06 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"





gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy into
the
battery by letting the generator output voltage stretch its legs so to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.

Bwahahahahaha!  So this was the original post?  Bwahahahahaha!

                                       ...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?

Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Unfortunately my workshop has been dismantled for refurbishing and most of
the stuff crammed into the shed - so no room to work in there either.

When I tried LTspice I found it a PITA to use - maybe while deprived of my
workshop I should give it another chance.

I love LT Spice. It's not hard to use, and well worth the short
learning curve.

Here, try this:

Thanks - might download it tomorrow.

I committed a Great Sin on Friday: I *designed* a circuit by fiddling
with Spice. It's a double-terminated LC filter feeding an opamp driver
diffamp, an ADA4950-1, with an offset generator voltage divider, and
all sorts of entangled loadings. Looking at the algebra, I bailed.
Since I'd probably want to sim it to check any computed (and stocked!)
parts values, why not just Spice it and fiddle?

ftp://jjlarkin.lmi.net/ESM_sig_in.pdf

John- Hide quoted text -

- Show quoted text -

I'm not seeing "all sorts of entangled loadings"? What kind of
response were you looking for?

 

[John Larkin]

On Mon, 5 Dec 2011 03:29:14 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

On Dec 4, 5:06 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"





gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy into
the
battery by letting the generator output voltage stretch its legs so to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.

Bwahahahahaha!  So this was the original post?  Bwahahahahaha!

                                       ...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?

Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Unfortunately my workshop has been dismantled for refurbishing and most of
the stuff crammed into the shed - so no room to work in there either.

When I tried LTspice I found it a PITA to use - maybe while deprived of my
workshop I should give it another chance.

I love LT Spice. It's not hard to use, and well worth the short
learning curve.

Here, try this:

Thanks - might download it tomorrow.

I committed a Great Sin on Friday: I *designed* a circuit by fiddling
with Spice. It's a double-terminated LC filter feeding an opamp driver
diffamp, an ADA4950-1, with an offset generator voltage divider, and
all sorts of entangled loadings. Looking at the algebra, I bailed.
Since I'd probably want to sim it to check any computed (and stocked!)
parts values, why not just Spice it and fiddle?

ftp://jjlarkin.lmi.net/ESM_sig_in.pdf

John- Hide quoted text -

- Show quoted text -

I'm not seeing "all sorts of entangled loadings"? What kind of
response were you looking for?

I want the ADC driver to swing from -0.75 to +0.75 diferential output
(into an LTC2242-12 ADC, which alone fills the next sheet of the
schematic) as the signal swings 0 to +3. The ADA4950 isn't a high
input impedance, and its VCM will be 1.25 volts. And I need to keep
the filter properly terminated.

John

 

[John Larkin]

On Mon, 5 Dec 2011 08:20:14 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

On Dec 5, 10:19 am, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Mon, 5 Dec 2011 03:29:14 -0800 (PST), Fred Bloggs





bloggs.fredbloggs.f...@gmail.com> wrote:
On Dec 4, 5:06 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"

gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy into
the
battery by letting the generator output voltage stretch its legs so to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.

Bwahahahahaha! So this was the original post? Bwahahahahaha!

...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?

Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Unfortunately my workshop has been dismantled for refurbishing and most of
the stuff crammed into the shed - so no room to work in there either.

When I tried LTspice I found it a PITA to use - maybe while deprived of my
workshop I should give it another chance.

I love LT Spice. It's not hard to use, and well worth the short
learning curve.

Here, try this:

Thanks - might download it tomorrow.

I committed a Great Sin on Friday: I *designed* a circuit by fiddling
with Spice. It's a double-terminated LC filter feeding an opamp driver
diffamp, an ADA4950-1, with an offset generator voltage divider, and
all sorts of entangled loadings. Looking at the algebra, I bailed.
Since I'd probably want to sim it to check any computed (and stocked!)
parts values, why not just Spice it and fiddle?

ftp://jjlarkin.lmi.net/ESM_sig_in.pdf

John- Hide quoted text -

- Show quoted text -

I'm not seeing "all sorts of entangled loadings"? What kind of
response were you looking for?

I want the ADC driver to swing from -0.75 to +0.75 diferential output
(into an LTC2242-12 ADC, which alone fills the next sheet of the
schematic) as the signal swings 0 to +3. The ADA4950 isn't a high
input impedance, and its VCM will be 1.25 volts. And I need to keep
the filter properly terminated.

John- Hide quoted text -

- Show quoted text -

OIC- well isn't that just constant-k design or something...

It would be cool if I could set up performance targets and let Spice
do the iterations for me. One of my guys does that sort or brute-force
circuit design - lets it run for hours - but he uses Octave and some
optimization program around that. He'll design filters by just pushing
poles and zeroes around iteratively.

I'm still constrained by wanting to use parts we have in stock, or
stock parts plus a minimum of new purchases.

Seems like I spend a lot of time trying to use stock parts, and use
parts aleady present on the schematic somewhere else. I did write a
program that finds the best in-stock resistors to hit a given ratio
and Thevenin impedance.

ftp://jjlarkin.lmi.net/Rugrat.jpg

but that's just a hint of what could be done. I want to tell Spice
"here's a list of parts I have in stock, and here's the output I want,
wake me up when you're done. Go to Digikey if you have to." I suppose
I could accomplish the same with a smart intern.

John

 

[Fred Bloggs]

On Dec 5, 10:19 am, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 5 Dec 2011 03:29:14 -0800 (PST), Fred Bloggs





bloggs.fredbloggs.f...@gmail.com> wrote:
On Dec 4, 5:06 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"

gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy into
the
battery by letting the generator output voltage stretch its legs so to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.

Bwahahahahaha! So this was the original post? Bwahahahahaha!

...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?

Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Unfortunately my workshop has been dismantled for refurbishing and most of
the stuff crammed into the shed - so no room to work in there either.

When I tried LTspice I found it a PITA to use - maybe while deprived of my
workshop I should give it another chance.

I love LT Spice. It's not hard to use, and well worth the short
learning curve.

Here, try this:

Thanks - might download it tomorrow.

I committed a Great Sin on Friday: I *designed* a circuit by fiddling
with Spice. It's a double-terminated LC filter feeding an opamp driver
diffamp, an ADA4950-1, with an offset generator voltage divider, and
all sorts of entangled loadings. Looking at the algebra, I bailed.
Since I'd probably want to sim it to check any computed (and stocked!)
parts values, why not just Spice it and fiddle?

ftp://jjlarkin.lmi.net/ESM_sig_in.pdf

John- Hide quoted text -

- Show quoted text -

I'm not seeing "all sorts of entangled loadings"? What kind of
response were you looking for?

I want the ADC driver to swing from -0.75 to +0.75 diferential output
(into an LTC2242-12 ADC, which alone fills the next sheet of the
schematic) as the signal swings 0 to +3. The ADA4950 isn't a high
input impedance, and its VCM will be 1.25 volts. And I need to keep
the filter properly terminated.

John- Hide quoted text -

- Show quoted text -

OIC- well isn't that just constant-k design or something...

 

[Ian Field]

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:2rqnd75rhlp6opv164golnl7kq6r5uo49v@4ax.com...

On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was
wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy
into
the
battery by letting the generator output voltage stretch its legs so
to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.


Bwahahahahaha! So this was the original post? Bwahahahahaha!

...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?


Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be
possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Unfortunately my workshop has been dismantled for refurbishing and most
of
the stuff crammed into the shed - so no room to work in there either.

When I tried LTspice I found it a PITA to use - maybe while deprived of
my
workshop I should give it another chance.


I love LT Spice. It's not hard to use, and well worth the short
learning curve.

Here, try this:


Thanks - might download it tomorrow.


I committed a Great Sin on Friday: I *designed* a circuit by fiddling
with Spice. It's a double-terminated LC filter feeding an opamp driver
diffamp, an ADA4950-1, with an offset generator voltage divider, and
all sorts of entangled loadings. Looking at the algebra, I bailed.
Since I'd probably want to sim it to check any computed (and stocked!)
parts values, why not just Spice it and fiddle?

Having noticed quite a few apps on the LT d/l page, I wondered what
switchercad does?

 

[John Larkin]

On Mon, 5 Dec 2011 18:16:30 -0000, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:2rqnd75rhlp6opv164golnl7kq6r5uo49v@4ax.com...
On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was
wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy
into
the
battery by letting the generator output voltage stretch its legs so
to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.


Bwahahahahaha! So this was the original post? Bwahahahahaha!

...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?


Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be
possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Unfortunately my workshop has been dismantled for refurbishing and most
of
the stuff crammed into the shed - so no room to work in there either.

When I tried LTspice I found it a PITA to use - maybe while deprived of
my
workshop I should give it another chance.


I love LT Spice. It's not hard to use, and well worth the short
learning curve.

Here, try this:


Thanks - might download it tomorrow.


I committed a Great Sin on Friday: I *designed* a circuit by fiddling
with Spice. It's a double-terminated LC filter feeding an opamp driver
diffamp, an ADA4950-1, with an offset generator voltage divider, and
all sorts of entangled loadings. Looking at the algebra, I bailed.
Since I'd probably want to sim it to check any computed (and stocked!)
parts values, why not just Spice it and fiddle?

Having noticed quite a few apps on the LT d/l page, I wondered what
switchercad does?

Switchercad is - I think - just another name for LT Spice.

John

 

[Charlie E.]

On Mon, 05 Dec 2011 08:45:15 -0800, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

<snip>

It would be cool if I could set up performance targets and let Spice
do the iterations for me. One of my guys does that sort or brute-force
circuit design - lets it run for hours - but he uses Octave and some
optimization program around that. He'll design filters by just pushing
poles and zeroes around iteratively.

I'm still constrained by wanting to use parts we have in stock, or
stock parts plus a minimum of new purchases.

Seems like I spend a lot of time trying to use stock parts, and use
parts aleady present on the schematic somewhere else. I did write a
program that finds the best in-stock resistors to hit a given ratio
and Thevenin impedance.

ftp://jjlarkin.lmi.net/Rugrat.jpg

but that's just a hint of what could be done. I want to tell Spice
"here's a list of parts I have in stock, and here's the output I want,
wake me up when you're done. Go to Digikey if you have to." I suppose
I could accomplish the same with a smart intern.

John

I remember in my old microwave filter class that we had just started
using Touchstone to design microstip filters. A couple of the guys
tried using the optimiser, and would set it up late and night, and
come in the next morning to see the results. They were doing a band
pass filter, but forgot to put in the 'stop' bands, just the pass
band.

The next morning, they came in to find it had optimised it to a single
transmission line... ;-)

Charlie

 

[Jim Thompson]

On Mon, 05 Dec 2011 11:29:16 -0800, Charlie E. <edmondson@ieee.org>
wrote:

On Mon, 05 Dec 2011 08:45:15 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

snip


It would be cool if I could set up performance targets and let Spice
do the iterations for me. One of my guys does that sort or brute-force
circuit design - lets it run for hours - but he uses Octave and some
optimization program around that. He'll design filters by just pushing
poles and zeroes around iteratively.

I'm still constrained by wanting to use parts we have in stock, or
stock parts plus a minimum of new purchases.

Seems like I spend a lot of time trying to use stock parts, and use
parts aleady present on the schematic somewhere else. I did write a
program that finds the best in-stock resistors to hit a given ratio
and Thevenin impedance.

ftp://jjlarkin.lmi.net/Rugrat.jpg

but that's just a hint of what could be done. I want to tell Spice
"here's a list of parts I have in stock, and here's the output I want,
wake me up when you're done. Go to Digikey if you have to." I suppose
I could accomplish the same with a smart intern.

John


I remember in my old microwave filter class that we had just started
using Touchstone to design microstip filters. A couple of the guys
tried using the optimiser, and would set it up late and night, and
come in the next morning to see the results. They were doing a band
pass filter, but forgot to put in the 'stop' bands, just the pass
band.

The next morning, they came in to find it had optimised it to a single
transmission line... ;-)

Charlie

On an intellaSys (*) project some village idiot manager hired some
clown peddling optimization software, and asked me to give the clown
one of my cells to optimize.

So I gave him my internationally famous band-gap that is flat as a
pancake and always starts up at very low VDD, any temperature, any
process corner.

The "optimizer" completely killed it and couldn't ever get it to work
again ;-)

So I was fired ;-)

(*) The rumor mill says they have crashed and burned... just another
investment black hole.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[John Larkin]

On Mon, 05 Dec 2011 11:29:16 -0800, Charlie E. <edmondson@ieee.org>
wrote:

On Mon, 05 Dec 2011 08:45:15 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

snip


It would be cool if I could set up performance targets and let Spice
do the iterations for me. One of my guys does that sort or brute-force
circuit design - lets it run for hours - but he uses Octave and some
optimization program around that. He'll design filters by just pushing
poles and zeroes around iteratively.

I'm still constrained by wanting to use parts we have in stock, or
stock parts plus a minimum of new purchases.

Seems like I spend a lot of time trying to use stock parts, and use
parts aleady present on the schematic somewhere else. I did write a
program that finds the best in-stock resistors to hit a given ratio
and Thevenin impedance.

ftp://jjlarkin.lmi.net/Rugrat.jpg

but that's just a hint of what could be done. I want to tell Spice
"here's a list of parts I have in stock, and here's the output I want,
wake me up when you're done. Go to Digikey if you have to." I suppose
I could accomplish the same with a smart intern.

John


I remember in my old microwave filter class that we had just started
using Touchstone to design microstip filters. A couple of the guys
tried using the optimiser, and would set it up late and night, and
come in the next morning to see the results. They were doing a band
pass filter, but forgot to put in the 'stop' bands, just the pass
band.

The next morning, they came in to find it had optimised it to a single
transmission line... ;-)

Charlie

Most elegant!

John

 

[Phil Hobbs]

On 12/5/2011 11:45 AM, John Larkin wrote:

On Mon, 5 Dec 2011 08:20:14 -0800 (PST), Fred Bloggs
bloggs.fredbloggs.fred@gmail.com> wrote:

On Dec 5, 10:19 am, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Mon, 5 Dec 2011 03:29:14 -0800 (PST), Fred Bloggs





bloggs.fredbloggs.f...@gmail.com> wrote:
On Dec 4, 5:06 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"

gangprobing.al...@ntlworld.com> wrote:

"John Larkin"<jjlar...@highNOTlandTHIStechnologyPART.com> wrote in message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

"John Larkin"<jjlar...@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.al...@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy into
the
battery by letting the generator output voltage stretch its legs so to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.

Bwahahahahaha! So this was the original post? Bwahahahahaha!

...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?

Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Unfortunately my workshop has been dismantled for refurbishing and most of
the stuff crammed into the shed - so no room to work in there either.

When I tried LTspice I found it a PITA to use - maybe while deprived of my
workshop I should give it another chance.

I love LT Spice. It's not hard to use, and well worth the short
learning curve.

Here, try this:

Thanks - might download it tomorrow.

I committed a Great Sin on Friday: I *designed* a circuit by fiddling
with Spice. It's a double-terminated LC filter feeding an opamp driver
diffamp, an ADA4950-1, with an offset generator voltage divider, and
all sorts of entangled loadings. Looking at the algebra, I bailed.
Since I'd probably want to sim it to check any computed (and stocked!)
parts values, why not just Spice it and fiddle?

ftp://jjlarkin.lmi.net/ESM_sig_in.pdf

John- Hide quoted text -

- Show quoted text -

I'm not seeing "all sorts of entangled loadings"? What kind of
response were you looking for?

I want the ADC driver to swing from -0.75 to +0.75 diferential output
(into an LTC2242-12 ADC, which alone fills the next sheet of the
schematic) as the signal swings 0 to +3. The ADA4950 isn't a high
input impedance, and its VCM will be 1.25 volts. And I need to keep
the filter properly terminated.

John- Hide quoted text -

- Show quoted text -

OIC- well isn't that just constant-k design or something...


It would be cool if I could set up performance targets and let Spice
do the iterations for me. One of my guys does that sort or brute-force
circuit design - lets it run for hours - but he uses Octave and some
optimization program around that. He'll design filters by just pushing
poles and zeroes around iteratively.

I'm still constrained by wanting to use parts we have in stock, or
stock parts plus a minimum of new purchases.

Seems like I spend a lot of time trying to use stock parts, and use
parts aleady present on the schematic somewhere else. I did write a
program that finds the best in-stock resistors to hit a given ratio
and Thevenin impedance.

ftp://jjlarkin.lmi.net/Rugrat.jpg

but that's just a hint of what could be done. I want to tell Spice
"here's a list of parts I have in stock, and here's the output I want,
wake me up when you're done. Go to Digikey if you have to." I suppose
I could accomplish the same with a smart intern.

John

That's more or less what I did with my electromagnetic simulator--a fast
clusterized FDTD engine with a big script wrapped round it to do the
multidimensional optimization, among lots of other things.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[John Fields]

On Mon, 05 Dec 2011 10:32:35 -0800, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 5 Dec 2011 18:16:30 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:2rqnd75rhlp6opv164golnl7kq6r5uo49v@4ax.com...
On Sun, 4 Dec 2011 20:54:52 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
message
news:12knd7123kfcrt1ttfdjopp5g4tfh6vcjd@4ax.com...
On Sun, 4 Dec 2011 19:21:21 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
message
news:qndnd7593gkmhghcknui03m42ihpi3hvjk@4ax.com...
On Sun, 04 Dec 2011 09:23:12 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 30 Nov 2011 13:09:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:

Tinkering with the old Sturmey archer bicycle dynamo, I was
wondering
whether it would charge a 1.2Ah SLA any better if the loading was
modified.

The generator is rated 6V/3W, but off load at a decent rate of knots
it
can
produce over a couple of hundred volts.

What I was wondering was whether its possible to get more energy
into
the
battery by letting the generator output voltage stretch its legs so
to
speak
and convert the excessive voltage down with a buck converter.

Can anyone advise on the practicality of this please?

Thanks.


Bwahahahahaha! So this was the original post? Bwahahahahaha!

...Jim Thompson

Perhaps Larkin would be happy to address Ian's question, "What I was
wondering was whether its possible to get more energy into the battery
by letting the generator output voltage stretch its legs so to speak
and convert the excessive voltage down with a buck converter"?


Well its what I wanted to hear anyway, I might start thinking about a
design
for a buck converter to try it out and see what happens, might be
possible
to get away with a MC34063 - failing that maybe a discrete component
design.

Unfortunately my workshop has been dismantled for refurbishing and most
of
the stuff crammed into the shed - so no room to work in there either.

When I tried LTspice I found it a PITA to use - maybe while deprived of
my
workshop I should give it another chance.


I love LT Spice. It's not hard to use, and well worth the short
learning curve.

Here, try this:


Thanks - might download it tomorrow.


I committed a Great Sin on Friday: I *designed* a circuit by fiddling
with Spice. It's a double-terminated LC filter feeding an opamp driver
diffamp, an ADA4950-1, with an offset generator voltage divider, and
all sorts of entangled loadings. Looking at the algebra, I bailed.
Since I'd probably want to sim it to check any computed (and stocked!)
parts values, why not just Spice it and fiddle?

Having noticed quite a few apps on the LT d/l page, I wondered what
switchercad does?


Switchercad is - I think - just another name for LT Spice.

---
Indeed.

Aren't you even beginning to be annoyed by the pilot fish who feeds on
your waste and considers you to be his source of chum?

--
JF